> > How come 10 mons == 9 mons 30 days?
>
> Because for purposes of comparisons, type interval assumes 1 month
> == 30 days (cf. interval_cmp_internal). Pretty grotty, I agree,
> but it's not easy to see how to do better.
Oh I see. Probably that's the reason why the standard does not allow
month-and-day-mixed interval.
--
Tatsuo Ishii